DE102008036798A1 - Method and device for controlling the flow velocity and for braking melt streams by magnetic fields, in particular during the tapping of metallurgical containers such as blast furnaces and furnaces - Google Patents

Abstract

The invention relates to a method for controlling the flow rate and to decelerating melt streams by magnetic fields, in particular during the tapping of metallurgical containers such as blast furnaces and furnaces. The method is characterized in that the melt stream in a closed guide element is passed through at least two in the flow direction of the melt in series successively arranged magnetic fields with a constant, opposite polarity, such that the magnetic field lines penetrate the melt flow over its entire cross section transversely and from the Magnetic fields are induced in the melt stream opposing voltages, are generated by the at least three successive eddy current fields in the melt stream, and that forces are generated by the interaction of magnetic fields and eddy currents, through which the flow rate of the melt stream can be reduced.

Description

The The invention relates to a method and devices for regulation the flow velocity and for braking non-ferromagnetic melt streams Magnetic fields, in particular during the tapping of metallurgical containers such as blast furnaces and smelting furnaces.

With a parallel patent application is already a generic control device has been proposed, which is characterized by a core ferromagnetic material having two poles, one gap to form a conductive element for a melt stream, and arranged on the core induction coils for generating a Magnetic field, which depends on the melt flow in between the poles arranged guide element acts.

at This control device is a closed magnetic circuit for generating a magnetic field used by the in the melt stream a Voltage is induced by which eddy currents are triggered in the melt stream, which, in cooperation with the magnetic field, generate forces that increase the flow velocity reduce the melt flow and increase again and the melt stream can slow down.

Of the Invention is based on the object, a method and devices for regulating the flow velocity and to decelerate non-ferromagnetic melt streams, which make it possible the magnetic field acting on the melt stream and through this generated eddy currents to increase to increase the forces acting on the melt stream.

These The object is achieved by the method with the features of claim 1 and the control devices according to the claims 6 and 7.

The under claims include advantageous and expedient developments of the method according to Claim 1 and the control devices according to claims 6 and 7th

The inventive method for regulating the flow velocity and for braking non-ferromagnetic melt streams, in particular when tapping metallurgical containers such as blast furnaces and furnaces is characterized in that the melt stream in a closed Guide element by at least two in the direction of flow of the melt in series one behind the other arranged magnetic fields with a constant, opposite polarity is conducted, such that the magnetic field lines the melt flow over the penetrate transversely through the entire cross section and from the magnetic fields in induced opposite currents to the melt stream, by the at least three successive eddy current fields in the melt stream be generated, and that by the interaction of magnetic fields and eddy currents personnel be generated by the flow rate of the melt stream dependent on from the magnetic field strengths can be reduced.

at a preferred embodiment This process is characterized by the magnetic flux of a closed Magnetic circuit over two opposing magnetic fields between each two poles a double, opposite voltage induced in the melt stream, so as to have a mutually reinforcing effect on the current of the central eddy current field.

By the double utilization of the magnetic flux of a closed magnetic circuit become the magnetic resistance in the iron core of the magnetic circuit and thus approximately halved the internal losses of the magnetic circuit.

A Variant of the method is that by the magnetic flux of two consecutively arranged, closed magnetic circuits over two opposing Magnetic fields between each two poles voltages in the melt stream be induced, such that a mutually reinforcing effect on the current of the central eddy current field.

By a dense arrangement of the on the melt stream in a gap between the two poles of a magnetic circuit acting magnetic fields is achieved that the gradient of the decrease of the magnetic flux to lateral gap edge as possible is great and that by the closely spaced arrangement of the column the path length the eddy currents shortened in the eddy current fields generated in the melt stream and the electrical resistance is reduced.

Of the fundamental Thought based on the fact that by the double utilization of the magnetic flux of a closed magnetic circuit a double, opposite, eddy current-amplifying Voltage is induced in the melt stream, wherein the magnetic Resistance in the iron core and thus halved the internal losses become.

Due to the series arrangement of several self-contained magnetic circuits with a double utilization of the magnetic flux, the effect on the melt flow is disproportionately increased by a disproportionate increase The number of steeper magnetic flux gradients is increased by a disproportionate increase in the number of amplified eddy current fields with their respective double interaction with the magnetic fields and by a double utilization of the inducing effect of the electric induction coils. The multiple use and the associated distribution of the eddy currents in the individual eddy current fields in the melt stream have a multiple and analog effect on the strengthening of the forces acting on the melt stream.

devices for regulating the flow velocity and for decelerating melt streams prepared according to the above work described method and in particular during tapping from blast furnaces are used are below with reference to schematic drawing figures explains which represent:

1 a perspective view of a control device according to a parallel patent application with a magnetic field of constant polarity for controlling the flow velocity and for braking a melt stream,

2 a diagram with the course of the magnetic flux density of the with the control device according to 1 generated magnetic field over the length of the exposure section of the magnetic field to the melt stream,

3 a perspective view of a first embodiment of the control device according to the invention,

4 a diagram with the course of the magnetic flux density of the with the control device according to 3 generated two magnetic fields and with the course of the magnetic flux density of the two magnetic fields of a control device downstream of this, another identical control device,

5 a perspective view of another embodiment of the control device,

6 the arrangement of a control device in front of the outlet opening of a taphole channel of a blast furnace and

7 a schematic representation of the double utilization of the magnetic flux inducing effect of electric induction coils.

The control device 1 to 1 preferred for tapping blast furnaces to control the flow rate and decelerate a melt stream 2 through a magnetic field 3 is used with constant polarity, has a core 4 made of ferromagnetic material, acting as a yoke 5 with two poles 6 . 7 is formed, which has a gap 8th for receiving a guide element 9 in the form of a pipe 10 for passing the melt stream 2 form. On the yoke 5 sit two induction coils 11 . 12 for generating a closed magnetic circuit 13 with the magnetic field 3 constant polarity between the two poles 6 . 7 that through field lines 14 is characterized.

The melt stream 2 occurs in the area 15 in the magnetic field 3 and leave this again in the area 16 , Upon entry of the melt stream 2 in the magnetic field 3 becomes in the melt stream in a plane perpendicular to the magnetic field lines 14 a tension 17 induced by the rule of Lenz eddy currents 18 in the melt stream 2 be generated. Through the interaction of magnetic field 3 and eddy currents 18 arise in the melt stream 2 the so-called Lorentz forces 19 , the flow direction a of the melt stream 2 are opposing and thereby a braking effect on the melt stream 2 exercise, by which the flow rate of the melt stream is lowered.

When leaving the exit area 16 of the magnetic field 3 arise in the melt stream 2 eddy currents 20 by interacting with the magnetic field 3 again Lorentz forces 21 generate the flow direction a of the melt stream 2 are oppositely directed and thus an additional braking effect to the braking effect of the Lorentz forces 19 in the entrance area 15 of the melt stream into the magnetic field 3 trigger.

For better illustration are in 1 the induced voltages 17 and the eddy currents 18 . 20 Drawn rotated by 90 ° from the horizontal plane to the vertical plane.

The diagram according to 2 shows the course of the magnetic flux density in Tessla of the control device 1 to 1 generated magnetic field 3 over the length L of the exposure section of the magnetic field 3 on the melt stream 2 , Because of the magnetic saturation in the iron, it is only possible with an economically unjustifiable effort to achieve a magnetic flux density that is above 2 Tessla. The expansion of the magnetic field 3 caused by the widening magnetic field lines 14 is clarified, in the gap 8th between the two poles 6 and 7 causes the magnetic flux density curve to be flat and far to the two edges of the gap 8th between the poles 6 . 7 expires. Within the magnetic field 3 becomes a corresponding electrical voltage depending on its strength and polarity 17 in the melt stream 2 induced as the driving force for the eddy currents 18 . 20 acts, so that the eddy currents the circuit only outside the magnetic field 3 can close. The lower one Gradient of decrease of magnetic flux density has expanded eddy current fields 18 . 20 with long rungs. In accordance with this comparatively long path length, comparatively high electrical resistances occur and accordingly correspondingly reduced eddy current strengths result.

The forces resulting from the interaction of eddy currents and magnetic field depend inter alia on the strength of the eddy currents, which, in turn, are inter alia dependent on the length of the current path. The shorter the current path, the lower the electrical resistance and the higher the resulting eddy current under otherwise given conditions. Since the current paths can only close in the rainfall outside the magnetic field, a magnetic field as sharply as possible at zero would be ideal for this purpose. In reality, a magnetic field but far out, like this 2 evident.

Besides that is it so that the eddy current on the resulting current path normally only once interacts with a magnetic field and therefore only once creates a force.

• 1. Das Magnetfeld hat zum Rand in Richtung des inversen zweiten Magnetfeldes den steilsten möglichen Gradienten und erzeugt damit den kürzest möglichen Strompfad, wie dies 3 verdeutlicht.
• 2. Dadurch, dass das benachbarte Magnetfeld die umgekehrte Polarität hat, wirkt es auf die gleiche Wirbelstromschleife gleichsinnig und verstärkend/verdoppelnd. Hierzu wird auf die nachfolgend noch ausführlich erläuterte 4 verwiesen.

So now if two magnetic fields with reversed polarity are placed close to each other, such that the magnetic field lines cross the melt flow transversely, then there are the following advantages:

• 1. The magnetic field has the steepest possible gradient to the edge in the direction of the inverse second magnetic field and thus generates the shortest possible current path, as this 3 clarified.
• 2. The fact that the adjacent magnetic field has the opposite polarity, it acts on the same eddy current loop in the same direction and amplifying / doubling. For this purpose, the following is explained in detail 4 directed.

The new control device 22 to 3 in particular in the tapping of blast furnaces for controlling the flow velocity and for braking a melt stream 2 is used in the taphole of a blast furnace, is one with two yokes 24 . 25 formed core 23 made of ferromagnetic material, the two pole pairs arranged one behind the other in series 26 . 27 with two poles each 28 . 29 ; 30 . 31 having. The two pole pairs 26 . 27 form two consecutively arranged column 32 . 33 for receiving a guide element 9 for passing the melt stream 2 as a pipe 10 or channel is formed. On the four pole shoes 34 - 37 the two yokes 24 . 25 of the core 23 are four induction coils 38 - 41 for generating two in the flow direction a of the melt stream 2 in series successively arranged magnetic fields 42 . 43 in a closed magnetic circuit 44 between the poles 28 . 29 ; 30 . 31 the two pairs of poles 26 . 27 arranged, with the two magnetic fields 42 . 43 have a constant, opposite polarity. Through the magnetic fields 42 . 43 be in the melt stream 2 opposite voltages 45 . 46 induced by in the melt stream 2 three consecutive eddy current fields 47 - 49 be generated, such that an mutually reinforcing effect on the current of the central eddy current field 48 between the two outer eddy current fields 47 . 49 results. Due to the interaction of magnetic fields and eddy currents, forces are generated in the melt stream through which the flow velocity of the melt stream can be reduced.

The Control device may be required to increase the on a melt stream acting braking force to an even number of pole pairs on the Length L the impact section of the magnetic fields on the melt stream be extended.

The diagram according to 4 illustrates the course of the magnetic flux density in Tessla shown in a solid line with the in 3 illustrated control device 22 in a closed magnetic circuit 44 generated two magnetic fields 42 . 43 over the length L of the action section of the magnetic fields on the melt stream and in dashed lines the magnetic flux density of the two magnetic fields of an identical, to the first control device 22 connected further control device.

The solid curve in 4 clarifies that in the control device 22 to 3 the magnetic flux in a closed magnetic circuit 44 is used twice and with opposite polarity. The resulting increase in the magnetic flux density results in a corresponding increase in the eddy current intensity. The double use in a closed magnetic circuit takes place in opposite directions, that is, the magnetic flux is effective in both the positive and in the negative flow direction. This increases the usable magnetic flux density for eddy current formation from about 2 Tessla to 4 Tessla in the same magnetic circuit. Further, the gradient for the decrease of the magnetic flux density in FIG 3 apparent area 50 between the two magnetic fields 42 . 43 extraordinary big. As a result, the path lengths of the eddy currents and thus the electrical resistances become smaller, which results in a corresponding increase in the current intensities.

The solid and dashed lines in 4 show the curve of the Magnetic flux density over the length of the exposure portion of the magnetic fields on the melt flow of two successively arranged control devices according to 3 with two consecutive, closed magnetic circuits, each with a double use of the magnetic flux. 4 illustrates that in a control device with a closed magnetic circuit, a steep curve of the magnetic flux density between two flat curves and results in two successively arranged control devices with two closed magnetic circuits and a double use of the magnetic flux in each magnetic circuit three steep curves between two flat curves of the magnetic flux density result. As a result, the increase in impact is clearly disproportionate.

In the control device 22 to 3 lie the column 32 . 33 between the poles 28 . 29 such as 30 . 31 and those in the columns 32 . 33 acting magnetic fields 42 . 43 close together. The magnetic fields 42 . 43 are in the area 50 , in which they meet, tightly bundled despite high magnetic flux density. From the correspondingly shortened current paths of the eddy currents and the double effect of the eddy currents it follows that the effect of the electromagnetic influence on the melt current more than doubles.

In 5 is another embodiment 51 the control device shown, the two control devices connected in series 1 according to 1 having.

The control device 51 is with two cores arranged one behind the other 4 . 4 made of ferromagnetic material, which is a yoke 5 with two poles 6 . 7 have a gap 8th form, wherein through the two in series successively arranged column 8th . 8th a guiding element 9 , in particular a taphole channel of a blast furnace for a melt stream 2 passed through. The control device 51 also has two each on the pole pieces of the two yokes 5 . 5 arranged induction coils 11 . 12 for generating two magnetic fields arranged one behind the other 42 . 43 with opposite polarity in two separate, closed, opposite magnetic circuits 13 . 13a , where the magnetic fields 42 . 43 in the melt stream 2 Eddy currents for generating a on the melt stream 2 trigger acting braking force.

Compared to a control device according to 3 , which works with a double use of the magnetic flux of a closed magnetic circuit, has the control device 51 to 5 with a simple use of the magnetic flux of two successively arranged, closed magnetic circuits a poorer efficiency, but with this control device, a significant gain of the eddy currents in the melt stream compared to the control device after 1 achieved with a closed magnetic circuit with a simple use of the magnetic flux.

While it in a control device with the maximum execution of the multiple use of the magnetic flux of a magnetic circuit only possible is to work with an even number of pole pairs, it is in a control device with a simple utilization of the magnetic flux several control loops possible, with both an odd and even number of Pole pairs to work. This may allow for better customization in limited space.

The various control devices 22 . 51 can be arranged as an attachment means in front of the outlet opening of the stitch hole of a blast furnace or in front of the outlet opening of the drainage channel of a melting furnace to the taphole or drain channel.

Out 6 goes the arrangement of two successively arranged control devices 22 according to 3 in front of the outlet opening of a taphole channel of a blast furnace. Inside a housing 52 are two closed magnetic circuits 44 with four columns 8th arranged for the double use of the magnetic flux of each magnetic circuit. The melt stream leaving the taphole channel of the blast furnace 2 flows through the pipe 10 passing through the four column 8th between the four pole pairs 26 . 27 ; 26 . 27 is guided, wherein the magnetic fields of the two magnetic circuits 44 over the length L on the melt stream 2 act.

In 7 are three induction coils 53 - 55 iron core of a multiple arrangement of induction coils with iron core for the production of closed magnetic circuits with a double utilization of the magnetic flux for the formation of eddy currents in a melt stream 2 represented by a pipe 10 flows. The spools 53 - 55 must be operated with alternately opposite polarity. In the illustration, the current directions of the respective right and left coil halves and the direction of the resulting magnetic flux 56 recognizable. Relative to the middle upper core 57 and its magnetic flux is not just its associated coil 54 effective, but also in this level, the right coil half of the coil 53 of the left core 58 and the left coil half of the coil 55 of the right core 59 , Thus, in this example, the left coil half of the coil acts 55 of the right core 59 both on the right core 59 as well as the middle core 57 magnetic-flux sourcing. This applies mutatis mutandis to all coil halves in a multiple arrangement, so that In the display plane, with the exception of the outermost left and right-hand coil halves, there is a double use of all the coil halves or the currents flowing therein. This achieves a further disproportionate increase in the effect.

1

Regulating device ( 1 )

2

melt stream

3

magnetic field

4

core

5

yoke

6

Pole of 5

7

Pole of 5

8th

Gap between 6 and 7

9

vane

10

pipe

11

Induction coil on 5

12

Induction coil on 5

13

closed magnetic circuit ( 1 and 5 )

13a

closed magnetic circuit ( 5 )

14

Field line of 3

15

Entry area of 3 For 2

16

Exit area of 3 For 2

17

Tension in 2

18

Eddy current in 2 within 15

19

Lorentz force in 2 within 15

20

Eddy current in 2 within 16

21

Lorentz force in 2 within 16

22

Regulating device ( 3 )

23

Core of 22

24

Yoke of 23

25

Yoke of 23

26

pole pair

27

pole pair

28

Pole of 26

29

Pole of 26

30

Pole of 27

31

Pole of 27

32

Gap of 26

33

Gap of 27

34

Pole shoe of 24

35

Pole shoe of 24

36

Pole shoe of 25

37

Pole shoe of 25

38

Induction coil on 34

39

Induction coil on 35

40

Induction coil on 36

41

Induction coil on 37

42

Magnetic field between 28 . 29

43

Magnetic field between 30 . 31

44

closed magnetic circuit

45

Tension in 2

46

Tension in 2

47

outer eddy current field

48

central Eddy current field

49

outer eddy current field

50

Area between 42 and 43

51

Regulating device ( 5 )

52

Casing ( 6 )

53

Kitchen sink ( 7 )

54

Kitchen sink

55

Kitchen sink

56

magnetic flux

57

middle core

58

left core

59

right core

a

Flow direction of 2

T

Tessla

L

Length of the exposure section of 3 on 2

Claims (11)

Method for controlling the flow velocity and for braking non-ferromagnetic melt streams by magnetic fields, in particular at the tapping of metallurgical containers such as blast furnaces and furnaces, characterized in that the melt stream in a closed guide element by at least two in the flow direction of the melt in series successively arranged magnetic fields with a constant , directed in opposite polarity, such that the magnetic field lines transversely penetrate the melt stream over its entire cross-section and induced by the magnetic fields in the melt stream opposing voltages, are generated in the melt stream at least three consecutive eddy current fields, and that by the interaction of Magnetic fields and eddy currents are generated forces by the flow velocity of the melt stream in dependence on the magnetic field strengths verm can be indert. Method according to claim 1, characterized in that that the magnetic flux of a closed magnetic circuit over two opposing magnetic fields between each two poles one double counter-rotating Induced voltage in the melt stream, such that a mutually reinforcing effect on the current of the central eddy current field. Method according to claim 2, characterized in that that by the double utilization of the magnetic flux of the closed Magnetic circuit of the magnetic resistance in the iron core of the magnetic circuit and thus approximately halved the internal losses of the magnetic circuit become. A method according to claim 1, characterized in that by the magnetic flux of two successively arranged, closed magnetic circuits via two opposing magnetic fields zwi In each case two poles voltages in the melt stream are induced, such that results in a mutually reinforcing effect on the current of the central eddy current field. Method according to one of claims 1 to 4, characterized by a dense sequential arrangement of the on the melt stream acting in a gap between the two poles of a magnetic circuit Magnetic fields, such that the gradient of the decrease of the magnetic flux as far as possible to the lateral edge of the gap is great and that by the closely spaced arrangement of the column the path length the eddy currents shortened in the eddy current fields generated in the melt stream and the electrical resistance is reduced. Device for controlling the flow velocity and for braking non-ferromagnetic melt streams, in particular when tapping metallurgical containers such as blast furnaces and furnaces according to the method according to claims 1 to 3 and 5, characterized by at least one by two yokes ( 24 . 25 ) formed nucleus ( 23 ) made of ferromagnetic material, the two in series successively arranged pole pairs ( 26 . 27 ) with two poles each ( 28 . 29 ; 30 . 31 ), the two successively arranged column ( 32 . 33 ) for receiving a guide element ( 9 ) for a melt stream ( 2 ) and four on pole shoes ( 34 - 37 ) of the two yokes ( 24 . 25 ) of the core ( 23 ) arranged induction coils ( 38 - 41 ) for the generation of two magnetic fields arranged one behind the other in series ( 42 . 43 ) in a closed magnetic circuit, which depends on the melt stream ( 2 ) in the guide element ( 9 ) passing through the column ( 32 . 33 ) between the poles ( 28 . 29 ; 30 . 31 ) of the two pole pairs ( 27 . 28 ) is guided. Device for regulating the flow velocity and for braking non-ferromagnetic melt streams, in particular for tapping metallurgical containers, such as blast furnaces and furnaces, according to the method according to claims 1, 4 and 5, characterized by at least two cores arranged one behind the other in series (US Pat. 4 . 4 ) of ferromagnetic material, each having a yoke ( 5 ) with two poles ( 6 . 7 ) having a gap ( 8th ), whereby through the two in series successively arranged column ( 8th . 8th ) a guiding element ( 9 ) for a melt stream ( 2 ) is passed, and two each on the pole pieces of the two yokes ( 5 . 5 ) arranged induction coils ( 11 . 12 ) for generating two magnetic fields arranged one behind the other ( 42 . 43 ) with opposite polarity in two separate, closed, counter-rotating magnetic circuits ( 13 . 13a ), wherein the magnetic fields in the melt stream ( 2 ) Trigger eddy currents to produce a deceleration force acting on the melt stream. Control device according to claim 6, characterized by an expansion possibility the same by even pole pairs. Control device according to claim 7, characterized by an expansion possibility same by even and odd pole pairs. Regulating device according to one of claims 6 to 9, characterized by an arrangement thereof as a pre-appliance in front of the outlet opening of the Taphole channels of a blast furnace or the outlet opening of the drainage channel of a Melting furnace. Regulating device according to one of claims 6 to 9, characterized by an arrangement thereof around the taphole channel a blast furnace or around the drainage channel of a melting furnace.